Best Way To Get 50?

I'm making a 2 tier cake for a friend and she needs 50 servings. I don't go by the charts because I think they are way too small of pieces and since I'm not charging (because I can't...lol) I want her to have normal sized pieces. I was hoping to do a 8 and 10, but even the "chart" says 48 servings. I would rather not have to do 10 and 12. Is there a better combo or am I stuck w/ the bigger cake? Oh, also there *may* be a half ball pan on top (kind of a 3rd tier).Any suggestions??